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mfjensen's avatar
mfjensen
Explorer
Jun 13, 2014

Keeping fresh water tank bacteria-free

I'm confused about how to keep the water in the fresh water tank from picking up bacteria/viruses -- such as the Legionaire's Disease that sitting water can develop.

I've seen the postings about running clorox through the system, rinsing then re-rinsings. Which sounds like a problem because where can you drain Clorox water? All the places I've stopped forbid it.

I've also had someone tell me that putting Sweet Water (?) in the tank eliminates any need for Clorox and is safe for all uses.

After 5 days of the "fresh" water being in the tank, my dogs have refused to drink it, so I don't believe that doing nothing is acceptable.

Advice would be greatly appreciated!!

Thank you,

Marlene

27 Replies

  • The amounts of chlorine in the tank are not going to bother a septic system, unless it is a true pro-biotic system. We sanitize our tank at home, in the driveway....no worse off than washing the car out there, since the small amount of chlorine in the tank isn't going to be very bothersome.

    I've never tried the Hydrogen Peroxide as a neutralizer, but do know that there are other products out there that will help get rid of the "smell/taste", but I'd still want to use the bleach to sanitize the system.....not sure about vinegar as a sanitizer? It cleans well, but not sure if it would kill bacteria in a water system?

    Tried and true sanitizing (and there is lots of information on sanitizing or de-winterizing the tanks.) so I'd just hit one of the YouTube videos or someething.
  • Check your manual. I'll bet it will give you sanitation instructions including measuring a fairly diluted amount of chlorine bleach into your system, circulating it, draining, and flushing. I drain it right in my gravel driveway without any damage. We're not talking a huge amount of bleach here, especially when diluted into your fw system.
  • rv2go wrote:
    You could use Hydrogen Peroxide


    I think that link is to a source where they are adding H2O2 to a small volume to be able to drink it. not to sanitize an entire tank of water. IIRC the HP you buy is about 4% strength. Pharmaceutical firms use a 30 % solution for surface sterilization. taking the 4% and diluting it 100 times gives you what? any RVer who says it works to sanitizing their tanks and water system probably didn't need sanitization in the first place.
    bumpy
  • Use the bleach at a rate of qtr. cup per 10 gallons - more will not do a better job. Let it set several hours or overnight. Then put in a 1/4 cup of hydrogen peroxide and drain. The H2O2 will immediately neutralize all the chlorine and the system is ready for use after a drain and refill. This waste solution will not hurt the CG's septic system because there's no chlorine left in it.
    You should not have bacteria growing every few days unless it's already in there. If that's the case then the method I suggested will re-mediate it.
    There are mixed thoughts in the industry about H2O2 alone being a sanitizer. So it's probably best to use bleach first.
  • This subject has been beat to death here on the forum, but it is of great interest to just about everyone and there is no absolutely correct answer.

    I just fill and flush with water from a municipal water source which has already been treated with chlorine. If the water has been in the tank for more than a few weeks, I drain, add a few gallons, drain, and then refill. We've been RVing for over 20 years and were boaters for over 25 years and never had a problem. (Our boat had a 60 gallon water tank that couldn't be drained but had to be pumped out. Still, never had a problem.)

    Now, for taste reasons, we use bottled water for coffee and drinking.

    If I were going to sanitize my coach's water tank, I'd use some "shock" that I use in our pool to kill bacteria that can grow when just normal amounts of chlorine is present. It is used about every two weeks or so. So, you can go to a pool supply place and buy a one lb bag of shock. Use a half teaspoon in your tank, let it sit for a few hours or a day, drain and refill. Shock has a very short life, like less than 24 hours. It will kill anything in the tank.

    Now, is that necessary? I don't think so. The ancients used cisterns and didn't have access to chlorine. The key was keeping the tank dark. All of our RV tanks (and our boat tank) are designed to keep light out. That's the key.

    Whatever you decide, good luck. As some have suggested, you can't be too safe, so do what you think is appropriate.
  • Marlene, twice a year I run a Vinegar solution through the fresh water system......